Martian crater honors milestone in spaceflight

On its way to the monster Endeavour Crater on Mars, NASA's Opportunity rover passed by a somewhat smaller divot in Meridiani Planum that now bears a highly symbolic name: Freedom 7.

The informal moniker for the 82-foot-wide (25-meter-wide) crater pays tribute to America's first human spaceflight, piloted by Mercury astronaut Alan Shepard 50 years ago today. Shepard's suborbita trip in the Freedom 7 capsule lasted only 15 minutes, but it signaled that the United States was still in the space race, three weeks after Soviet cosmonaut Yuri Gagarin became the first human in orbit. Shepard's success was quickly followed by President John Kennedy's campaign to put an American on the moon by the end of the decade.

That goal was achieved in 1969, and Shepard himself walked on the moon (and took a golf swing or two) during the Apollo 14 mission in 1971 — capping an adventure that started with that first Project Mercury flight 10 years earlier.

"Many of the people currently involved with the robotic investigations of Mars were first inspired by the astronauts of the Mercury Project who paveds the way for the exploration of our solar system" Scott McLennan of the State University of New York at Stony Brook, this week's long-term planning leader for the rover science team, said in a NASA news release.

Freedom 7 is the largest of a cluster of about eight craters which are thought to have formed after sand ripples in the area last migrated, which would be about 200,000 years ago. "They're from an impactor that broke up in the atmosphere, which is quite common," said Matt Golombek, a rover team member from NASA's Jet Propulsion Laboratory.